Four-year-old Maddie was taken from the family’s holiday apartment in Praia Da Luz on May 3, 2007.
Maddie’s twin siblings were in the apartment when she was snatched as her parents dined at a nearby restaurant.
Despite searches and an investigation led by Portuguese police, Maddie has still not been found and her parents do not know if she is alive.
Scotland Yard recently opened up their own investigation and sent officers to the holiday resort to hunt for clues surrounding Maddie’s disappearance.
Speaking at the church service, Kate thanked people for their support.
She said: ‘Having your support has made a huge difference, so thank you.’
Maddie’s father Gerry then said: ‘I would just like to echo what Kate said and thank you all for coming to support us over the past seven years.’
Referring to the UK police’s investigation, he continued: ‘They are chipping away and obviously there is new evidence so we are going to continue to hope that we will get a happy outcome.’
Kate recently spoke the BBC about her backing of a new alert system to be put in place if a child is abducted.
She said: ‘When a child is abducted, families are devastated and entire communities are torn apart.’
‘The agony of not knowing where your child is almost impossible to imagine.’